package concurrent;

import java.util.Random;
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;

public class CyclicBarrierDemo  {

    public static class Soldier implements Runnable {

        private String soldier;
        private final CyclicBarrier cyclicBarrier;

        public Soldier(String soldier, CyclicBarrier cyclicBarrier) {
            this.soldier = soldier;
            this.cyclicBarrier = cyclicBarrier;
        }

        @Override
        public void run() {
            try {
                cyclicBarrier.await();
                doWork();
                cyclicBarrier.await();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (BrokenBarrierException e) {
                e.printStackTrace();
            }
        }

         void doWork() {
            try {
                Thread.sleep(Math.abs(new Random().nextInt()%10000));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(soldier + " mission is over");
        }
    }

    public static class BarrierRun implements Runnable {

        boolean flag;
        int N;

        public BarrierRun(boolean flag, int n) {
            this.flag = flag;
            N = n;
        }

        @Override
        public void run() {
            if (flag) {
                System.out.println("司令：[士兵"+ N +"个， 任务完成]");
            } else {
                System.out.println("司令：[士兵"+ N +"个， 集合完毕]");
                flag = true;
            }
        }
    }

    public static void main(String[] args) {
        final int N = 10;
        Thread[] allSoldier = new Thread[N];
        boolean flag = false;
        CyclicBarrier cyclicBarrier = new CyclicBarrier(N, new BarrierRun(flag, N));
        System.out.println("go!");
        for (int i = 0; i< N; i++) {
            System.out.println("士兵" + i + "报道");
            allSoldier[i] = new Thread(new Soldier("士兵"+i, cyclicBarrier));
            allSoldier[i].start();
        }

    }

}
